Technical Field
The present disclosure relates to digital video processing, and more particularly, to filtering of motion vectors.
Description of the Related Art
Digital video compression is used to reduce the quantity of data used to represent digital video images. Digital video compression and decompression schemes often result in inaccurate object motions appearing within the video due to a particular compression scheme used to achieve a large compression ratio, moving objects being blocked in a video frame by other objects, a very low bit rate requirement, and/or due to skipped or missing video frames. This is because in digital video compression, motion vector (MV) data based on estimated motion or estimated stillness of objects or picture fragments between frames of the digital video are used to replace actual originally captured data.
For example, in two adjacent digital video frames, finding the best correlation of a predefined picture fragment from one of the frames onto another frame results in an initial estimation of motion vectors related to the fragment. If the fragment is defined to be of a basic shape, for instance a square shape, the problem of finding an accurate MV arises when the shape comprises picture elements (pixels) from different objects moving in different directions and/or at different speeds. If a MV is assigned to a center pixel of the fragment and there are two objects in the fragment, there is a chance that the center pixel which belongs to one of the objects will be assigned to a MV corresponding to the other object.